1. Field Of The Invention
The present invention pertains to crane apparatus having an extendable boom which may be mounted on small trucks, manually movable carts for use in the building and construction trade, or otherwise as needs dictate.
2. Description Of The Prior Art And Objectives Of The Invention
Cranes have become increasingly used in various trades in recent years for a variety of hoisting and lifting operations. Stationary cranes are oftentimes used for tall building and skyscraper construction whereas smaller, mobile cranes are employed for other commercial work. A third group of cranes consist of compact designs which are mounted on small trucks or which could be positioned on carts which can be manually rolled from site to site within a building or the like for handling heavy loads such as production machinery.
Smaller cranes in the past have had limited operating capabilities, were expensive to manufacture and did not have the precision controls required for safe and precise movement. Therefore, it is an objective of the present invention to provide crane apparatus suitable for mounting on a truck or a hand cart which includes a pendant control having a series of two stage switches to control the speed of operation.
It is yet another objective of the present invention to provide crane apparatus having a welded boom construction to provide maximum total machine rigidity under load.
It is still another objective of the present invention to provide a crane control apparatus which has a dual hydraulic pump unit whereby hydraulic fluid can be delivered to hydraulic motors or cylinders either under high or low volume as controlled by pendant switches, for speed control.
It is also an objective of the present invention to provide crane apparatus having a turret with an adjustable worm gear assembly which will eliminate "play" when then turret is not operating.
It is still another objective of the present invention to provide a pendant control which is affixed to the stationary base of the crane apparatus for convenience, safety and ease of use during operation and also providing continuous turret rotation.
Various other objectives and advantages of the present invention become apparent to those skilled in the art as a more detailed presentation is presented below.